In the last few years connection devices have been developed to connect optical fibres with each other, so that the fiber ends are situated exactly axially opposite to each other. An example on such a connection device is shown in the swedish patent 426 882. A difficulty with connection of optical fibres at the ends to each other is their small diameter, which amounts to one or a few tenths of a millimeter, while the optical core thereof can have a diameter of 10-50 um. An eccentricity of the end portions of the fibre cables of one or a few thousand parts of a millimeter thus constitutes a rough deviation, whereby the losses increase drastically. Very high demands are thus put on the tolerances of the connection device, which leads to complicated constructions and high manufacturing costs.
Connection devices are previously known (IBM Technical Disclosure Bulletin, volume 21 on Oct. 5, 1978) for connection of optical fibres, where the fibre is guided and fixed by three axial rods arranged in a conical guiding body, which is radially slotted. The guiding body is insertable in a receiving means with corresponding conicity, whereby the guiding body by means of a cap nut can be pressed into the receiving means. Since the conical part of the guiding body in its rear part passes over into a solid annular shaped member, a bringing together of the guiding body in the receiving means only the front part of the conical part will be compressed, which means that the fibre only is guided and fixed in its front end. If the tightening pressure is increased to get a larger part of the fibre fixed inside the guiding body the pressure stress at the extreme ends of the guiding body will become so large that the fibre will be crushed.
Through DE-B2-27 57 215 is known a connection device where a number of rods are surrounded by a slotted circlip, the function of which is to keep the rods together and thereby form a receiving means, in which from both ends is insertable a connection pin. If the fibre diameter in one of the connection pins is larger or smaller than the fibre diameter in the other connection pin, only one of the connection pins will be fixed in the receiving means, while the other will take an eccentric position relatively the first connection pin.